For the first time ever, Tricare will host an open enrollment period for military families and retirees who want to change their coverage plans.

Currently, changing between Tricare Prime and Tricare Select, previously known as Tricare Standard, is easy and typically not time sensitive for active-duty families and retirees. If you want to change and your military status or location qualifies you to do so, you can simply call your Tricare regional contract and ask to be swapped. Sometimes, there is a waiting period before you can switch from Tricare Select to Tricare Prime, but it is often waived.

Starting Jan. 1, however, the ability to switch back and forth at will is going away. Here's what you need to know:

1. To change plans, you must have a "qualifying life event." Along with the change to Tricare Select from Tricare Standard, the Defense Health Agency did away with the ability to switch back and forth. Starting Jan. 1, you'll need to experience a "qualifying life event" (QLE). What does that mean? Tricare officials created a list based off industry standards. It includes things like a move, job loss and being recaptured from a civilian doctor into the Military Treatment Facility system. You can see a complete QLE list on Tricare's website.

2. Tricare's QLE list does not include pregnancy. While giving birth is a qualifying event that would let you switch between plans, pregnancy is not. That means military spouses who think they might get pregnant and who do not want to be seen for their pregnancy within the military treatment facility system should register for Tricare Select during the annual open enrollment period.

3. Open enrollment happens only one time each year. Once a year, all Tricare users will have the chance to switch plans without first having one of those QLEs. That window will run from mid-November to mid-December. Starting Jan. 1, 2019, if you missed that window, you will not be able to change plans.

4. Other Tricare users can switch at any time. Tricare users on Tricare Reserve Select, Tricare Retired Reserve and Tricare Young Adult don't have to worry about QLEs. Instead, they can enroll or un-enroll at any time. That's because those programs, known as "purchased plans," are based on other eligibility factors such as age and Guard or Reserve status.

5. The newly available vision plans also have enrollment rules. Looking to take advantage of the vision plan now available for military families through the Federal Employees Dental and Vision Insurance Program (FEDVIP)? That program has its own open enrollment rules. You will also need to enroll or make changes to your coverage during the annual open enrollment or during a qualifying life event.